S3170G Servo Case - Futaba FUAS4158 (No Packaging)  [FUAS4158]

Product Notes and Use

The Futaba FUAS4158 servo case set is provided as an outer shell replacement for the S3170G servo and is shipped without retail packing. It replaces the existing housing to protect internals while servicing and to bring back original fit where the case is cracked or worn.

Designed with the S3170G in mind, this is a mechanical housing swap rather than an upgrade to the servo electronics. It assists routine workshop procedures such as disassembly for inspection, bearing access, and component reassembly during tuning.

Installation guidance: remove the horn and output gear as required, organise shims and bearings on a clean surface, move internal components into the replacement shell, and tighten screws evenly to avoid deforming the case. After reassembly, operate the servo on a bench at a safe voltage to check travel range and neutral position before fitting back into the model.

As a passive replacement, the case does not alter performance electronically but can improve mounting repeatability and alignment, which helps maintain consistent steering response during tuning.